The municipality of Astorga (12,015 inhabitants in 2010, therefore the
3rd most populous municipality in the province; 4,678 ha; municipal website) is located in the center of the Province of León, 50 km of León. The municipality is made of the town of Astorga and of the villages of Castrillo de los Polvazares (70 inh.), Murias de
Rechivaldo (109 inh.), Santa Catalina de Somoza (60 inh.) and
Valdeviejas (167 inh.).

Astorga emerged as a Roman camp set up in 19 BC by the 10th Legion
("Legio X Gemina") after the submission of the Asturs, whose
settlement was renamed Asturica Augusta. Very interested in the nearby
gold mines, the Romans made a few decades later Asturcia the capital
of the "conventus asturum". Remains of ditches, of thermae, of a
temple dedicated to August, of the forum and of the sewage system have
been preserved until now. The most famous significant Roman remains
are found in the so-called Mosaic's House, dated from the 1st century
AD; the house was paved in the late 2nd century with mosaics
representing an allegory of autumn and the myth of Orpheus.
In the 4th century, the town was reorganized and surrounded with
walls. At the end of the 11th century, the first cathedral was built
in Romanesque style and the street arrangement was redefined, blurring
the Roman hippodamic (designed for horse-driven cart traffic) template.

Astorga was made in the 14th century the seat of a Marquisate ruled by
the Osorio. Bishop Alvaro Osorio y Guzmán (1440-1463) started in 1444 the building on the today's cathedral; reusing some parts of the early
Romanesque cathedral, the Astorga cathedral was built in Spanish
flamboyant Gothic style, also used for the Seville and Salamanca
cathedrals. The baroque facade was added in 1708 by
Pablo Antonio Ruiz. The old tower, started in 1678 and damaged in 1775
during the Lisbon earthquake, was achieved in 1965 only; the new tower
was built in 1692-1704.

In 1545, María Cortés de Zúñiga, the daughter of the conquistador Hernán Cortés, married Álvaro Pérez Osorio, the heir of the Marquisate
of Astorga. A local tradition says that part of María's dowry was made of chocolate imported from Mexico, which started chocolate industry in
Astorga; cocoa was transported from the port of Corunna to Astorga
via the dense network of muleteer's trails, also used to bring fish to
the town. In 1753, Astorga housed eight chocolate factories; In 1914,
"Chocolate Town" housed 49 chocolate factories, including the most
important in Spain. Following the saturation of the market, several
chocolate makers emigrated to Europe and South America, spreading
Astorga's fame worldwide. The Municipal Chocolate Museum (website) was
inaugurated in 2005, based on the collection accumulated by the trader
José Luis López García (1927-2010); the museum is housed in the former factory and residence of Magín Rubio González, purchased in 1996 by the municipality.

The flag of Astorga (municipal website) is red with the municipal coat of arms in the middle.

The coat of arms of Astorga is "Gules a branch of oak proper. The
shield surmounted by a Marquis' coronet [and placed over a parchment
or]". The coat of arms of Astorga is one of the oldest known in the
León Province, but the origin and meaning of the oak branch are
unknown yet. Pedro Junto, in a document published in 1635 in Pamplona and the oldest description of the arms, gives a fanciful explanation based on the (remote) similarity between "Roma" (Rome) and robur (an oak); the red field would represent the Roman camp and the blood shed by enemies assaulting it. A more modern interpretation presents the oak branch, depicted as nearly dry, as the symbol of force increasing with time.
The coat of arms is historical, used "since immemorial times",
and, therefore, without date of adoption or proper legislation.